First, welcome to TFP Streetbuc!
I want to clear up your possible misconception on chlorine levels and liner damage/comfort. It is not directly the FC level that causes these things, but the active chlorine level and the CC level. A low active chlorine level is important for comfort and minimal breakdown of swimsuits, hair, and liners, but as with all industry suppliers the Nature2 people ignore the incredible buffering effect of CYA. The FC/CYA ratio we follow here recommends a minimum of 7.5% FC to CYA. So at 60 the minimum FC level should be kept above 5, which seems high but because of that buffering effect is actually only as strong as 0.1 ppm FC in water with no CYA. Even our SLAM levels are perfectly safe to swim in and are less active than a pool with no CYA and 3 ppm FC, like many indoor public pools.
A big contributor to unpleasant water is Combined Chlorine (CC). This is the byproduct of chlorine after it oxidizes something and is the primary cause of "chlorine smell". Keeping these levels low (which keeping FC at TFP recommended levels helps greatly) gets rid of most smells associated with pools as well as enhances swimmer comfort. pH also plays a role in comfort, but it is usually a personal preference what pH is more comfortable.
Copper does kill algae and silver kills algae and also many bacteria, so the Nature2 does allow you to maintain lower FC levels. Algaecides and phosphate removers also help to hinder algae growth, allowing lower FC levels. There always needs to be some residual FC in a pool to kill bacteria but it takes far less to kill bacteria as it does to kill algae, which is why you need something additional to help kill algae.
If you really want to maintain a lower FC than TFPC recommendations then I suggest either using a polyquat algaecide or phosphate remover instead of a mineral system, and following the rest of the TFPC guidelines with a lower FC/CYA ratio. This should give you a relatively trouble free experience with lower chlorine levels. However I will say from experience that I had a Frog system, which is similar to the Nature2. I followed their guidelines and didn't have any significant problems until my winter cover blew off and I had a terrible algae bloom, which led me to this forum. Since I removed the Frog and began maintaining my water to TFPC and the FC/CYA ratio I have noticed a significant improvement to my water quality. It doesn't really have a smell, feels fine, and looks beautiful. So I can tell you from personal experience that the higher FC does not cause any negative experiences, nor have I gotten any complaints. It also came with a significant cost savings too, which is pretty nice.
Whichever method you choose going forward I hope you will continue to use the forum and expand your knowledge of pool care!
